11.2.0.3 - sql slow

 We are having a query which was running fine in 11.2.0.1 where as in 11.2.0.3 the query is running slow.Everything (parameter)  is same on both the versions.

SELECT /*+ FIRST_ROWS(10) */ * FROM (SELECT PoHeade rsAllPEO.SEGMENT1 , PoHeadersAllPEO.PO_HEADER_ID , PoHeadersAllPEO.VENDOR_ID , PoHeadersAllPEO.CURRENCY_CODE , PoHeadersAllPEO.SOLDTO_BU_ID , HzPartiesPEO.PARTY_NAME as party_name, SupplierPEO.PARTY_ID AS PARTY_ID, SupplierPEO.SEGMENT1 AS SUPPLIER_NUMBER , PoHeadersAllPEO.TERMS_ID , SupplierSiteDPEO.VENDOR_SITE_ID , SupplierSiteDPEO.VENDOR_SITE_CODE , BusinessUnitUsagePEO.bu_name bu_name , PersonNameDPEO.FULL_NAME FROM PO_HEADERS_ALL PoHeadersAllPEO , PER_ALL_PEOPLE_F_V PersonDPEO , PER_PERSON_NAMES_F_V PersonNameDPEO , POZ_SUPPLIERS SupplierPEO , FINANCIALS_SYSTEM_PARAMS_ALL FinancialsOptio nPEO , FUN_BU_USAGES_V BusinessUnitUsagePEO , POZ_SUPPLIER_SITES_ALL_M SupplierSiteDPEO , POZ_SITE_ASSIGNMENTS_ALL_M SupplierSiteAssignmentDPEO, HZ_PARTIES HzPartiesPEO WHERE PoHeadersAllPEO.TYPE_LOOKUP_